This paper aims to discuss the behavior of the proprietary real-time simulator (RTS) during testing the coordination of distance relay protections in power engineering. During the construction process of the simulator, the mapping of various dynamic phenomena occurring in the modeled part of the power system was considered. The main advantage to the solution is a lower cost of construction while maintaining high values of essential parameters, based on the generally available software environment (MATLAB/Simulink). The obtained results are discussed in detail. This paper is important from the point of view of the cost-effectiveness of design procedures, especially in power systems exploitation and when avoiding faults that result from the selection of protection relay devices, electrical devices, system operations, and optimization of operating conditions. The manuscript thoroughly discusses the hardware configuration and sample results, so that the presented real-time simulator can be reproduced by another researcher.